Subscriptions

Send a subscribe message to start receiving events:

{"action": "subscribe", "filters": {"action_types": ["order", "fill"]}}

Response:

{"action": "subscribed", "id": "default", "sub_id": 1, "total_subs": 1}

Give your subscription a name for easier management:

{"action": "subscribe", "id": "btc-orders", "filters": {"action_types": ["order"], "assets": ["BTC"]}}

Multiple subscriptions

You can have multiple active subscriptions on one connection. Each gets its own ID:

{"action": "subscribe", "id": "orders", "filters": {"action_types": ["order", "fill"]}}
{"action": "subscribe", "id": "btc-cancels", "filters": {"action_types": ["cancel"], "assets": ["BTC"]}}

An event matching multiple subscriptions is sent once (deduplicated per connection).

Unsubscribe

{"action": "unsubscribe", "id": "btc-cancels"}

Ping/pong

The server sends WebSocket ping frames every 30 seconds. Most libraries handle this automatically. You can also send application-level pings:

{"action": "ping"}

Response:

{"action": "pong"}

Common subscription patterns

Everything (firehose):

{"action": "subscribe"}

~6,500 events/sec on mainnet. Both pre-consensus and confirmed. Orders and fills only (recommended for most users):

{"action": "subscribe", "filters": {"action_types": ["order", "fill"]}}

~200 events/sec. Every order placement and trade execution. Track a specific wallet:

{"action": "subscribe", "filters": {"addresses": ["0xd071d6d6ea52f5aa34b79e47f908ee48c8215837"]}}

Only events from this address. Works across all asset types. BTC only:

{"action": "subscribe", "filters": {"assets": ["BTC"]}}

All event types but only for Bitcoin. Pre-consensus signals:

{"action": "subscribe", "filters": {"action_types": ["cancel", "cancelByCloid", "batchModify"]}}

Cancel and modify actions before they are committed. Arrives ~1 second early. Confirmed orders only (no noise):

{"action": "subscribe", "filters": {"action_types": ["order"]}}

The "order" umbrella matches: order, order_filled, order_canceled, order_rejected. New resting orders have type order with data.status: "open". Prediction markets:

{"action": "subscribe", "filters": {"assets": ["#39890"]}}

Track a specific outcome token.

Subscription limits

Tier	Max connections	Max subscriptions
free	1	1
starter	5	50
growth	10	500
pro	150	5,000
enterprise	500	100,000

Exceeding your subscription limit returns an error:

{"error": "subscription limit reached for growth tier (max 500)"}

HyperEVM transactions

Subscribe to pre-block HyperEVM smart contract transactions using the evmRawTx action type:

{
  "action": "subscribe",
  "filters": {
    "action_types": ["evmRawTx"]
  }
}

Events arrive with consensus: "pre" and a data field containing the raw RLP-encoded signed transaction as a hex string. See Event Types for the full decoding example.

Real-time Streaming

Event Types

System

Multiple subscriptions

Unsubscribe

Ping/pong

Common subscription patterns

Subscription limits

HyperEVM transactions

​Subscribe

​Subscribe with custom ID

​Multiple subscriptions

​Unsubscribe

​Ping/pong

​Common subscription patterns

​Subscription limits

​HyperEVM transactions

Subscribe

Subscribe with custom ID

Multiple subscriptions

Unsubscribe

Ping/pong

Common subscription patterns

Subscription limits

HyperEVM transactions